This invention relates generally to a structural means for mounting ballast circuit components in luminaires utilizing discharge lamps and more particularly to such mount construction for sealed circuit components thereof.
Various type luminaires utilizing discharge lamps are known which generally comprise a housing containing a power module supporting ballast components and an optics compartment which includes a socket member for the lamp. Representative luminaires for use in various outdoor lighting applications are disclosed in U.S. Pat. Nos. 4,358,816; 4,426,676; and 4,434,456 all assigned to the assignee of the present invention. A commonly employed luminaire of this type for street and roadway lighting is described in the 4,426,676 patent which comprises an upper housing, whose underside is closed at the front end by a refractor supported in a frame member and at the rear by a hinged door. The ballast assembly for said luminaire construction is generally mounted on the door member for ease of installation and maintenance. A high intensity sodium vapor lamp, a mercury discharge lamp or a metal halide lamp commonly provides the illumination source in such luminaire construction having operatively associated lamp ballast means of the type disclosed in U.S. Pat. No. 4,472,015, also assigned to the present assignee. As therein illustrated with respect to a typical lamp ballasting circuit for use with a high intensity sodium vapor lamp embodiment, the ballast comprises a power module interconnected with a plug-in starting aid circuit and which can all be physically mounted in the luminaire construction as above indicated. The described power module embodiment includes a line power factor improvement capacitor while the starting aid circuit includes a second capacitor used in generating a series of high frequency pulses to initiate the arc discharge. It can be appreciated therefrom that capacitor devices are widely employed in lamp ballasting circuitry of many types as further indicated in said reference by the mention of still other ballast means for mercury discharge and metal halide discharge lamps. Indoor luminaires having a generally similar assembly are also well known and which frequently employ the above mentioned mercury discharge, sodium discharge and metal halide discharge lamps. Accordingly, the lamp ballasting means employed in said indoor luminaires is of the same type employed for outdoor luminaires and within the selected ballast circuitry also being housed entirely with the luminaire enclosure. A representative indoor luminaire adapted for exposure to severe weathering conditions or extremely corrosive atmospheres experienced in various industrial environments is disclosed in still further commonly assigned U.S. Pat. No. 4,704,665 and which can employ all of the aforementioned discharge lamps to provide the source of illumination.
Various attempts have been made to reduce the cost and complexity of mounting the circuit components for a ballast assembly in a discharge lamp luminaire. For example, the more than 50 different capacitors commonly employed in ballast circuits have different shapes and overall dimensions so that a large number of mounting brackets have become necessary and to further include many multipart bracket constructions. Additionally, it is often desirable to mount ballast circuit components in a vertical spatial orientation with respect to the mounting surface as distinct from the horizontal mount orientation now frequently employed in order to save space on the selected mounting substrate as well as provide easy access to the terminal connections. A ballast assembly mounted upon a substantially horizontal mounting surface would meet these objectives by mounting the particular circuit components with the terminals upright in a vertically extending direction whereas a wall mounted luminaire having a back plate as the ballast mounting surface satisfies the same objectives with the ballast circuit component or components being mounted so as to extend in a substantially horizontal direction. The nature and extent of difficulties now being experienced in satisfying such objectives with representative capacitor devices is largely due to differences found in cross sectional size and shape of these devices as well as to length variation. The conventional capacitor device and still other circuit components or devices commonly employed in a discharge lamp ballast are housed in sealed containers having top and bottom portions connected by side portions with electrical terminal means being secured to said top portion. Both circular and oval cross section ballast circuit components are employed with manufacturing tolerances enabling reasonably close control of the cross-sectional dimensions to be provided but with far less consistent dimensions being provided on device length. Accordingly, the common practice has been to mount these devices on their side with respect to the mounting surface while understandably sacrificing some mounting space in doing so. The various past attempts to mount such ballast circuit devices vertically with respect to the mounting surface have met with little success. For example, one prior art bracket includes a hooked end to physically engage the capacitor top portion and exert a downward force thereby requiring individual bracket lengths to satisfy capacitor length variation. Such mount construction further required retaining means to be added on the mounting surface to forestall lateral movement of the installed capacitor device. Significant costs can be associated with such mounting means upon considering the inventory of hooked brackets needed along with a possible further need to cast retainer means in the body of a metal or plastic luminaire housing. A different prior art capacitor mounting bracket frictionally engages the side portions of said device with a clamping arrangement. Again, excessive variation in the capacitor physical dimensions required an adhesive to forestall movement after assembly while the installation of such clamping arrangement also proved difficult. A still different prior art means to mount the illustrated capacitor device in a vertical spatial orientation employs an L shaped bracket secured to the capacitor side portions with a horizontal clamp. The assembly labor required to install such clamping means proved extensive with additional costs being experienced from injury or destruction of the capacitor devices due to excessive lateral compressive forces. A still different unsuccessful clamping arrangement to vertically mount the illustrated capacitor device again employs a horizontal clamp having overlapping tab fastening means formed in a Z shaped configuration which compressed to frictionally engage the clamp around the capacitor side portions. Such clamping means also proved expensive as well as provided only a flimsy mounting of the installed capacitor device.
Accordingly, one object of the present invention is to provide improved ballast circuit mounting means for use in a discharge lamp luminaire which is simpler to construct and easier to install.
A different object of the present invention is to provide a mounting means whereby a ballast circuit component or components can be physically secured to a mounting surface in a discharge lamp luminaire in various spatial orientations.
Still a different object of the present invention is to provide a discharge lamp luminaire having a ballast circuit component or components more rigidly mounted therein so as to be vertically positioned with respect to the mounting surface.
A still different object of the present invention is to provide mounting means for a ballast circuit component or components in a discharge lamp luminaire so as to be easily disengaged and reengaged by the customer, if desired, for repair or replacement of the component device.
These and still further objects of the present invention will become apparent upon considering the following detailed description for the present invention.